bug#9987: RFE: 'groups' command ADD command switches "-0", and "-1"

[Linda Walsh]

I'd like to request an RFE for the groups command to add 2 switches:

-1 - print groups  in 1 column (cf. ls -1)
-0 - print groups followed by null (cf. find et al)

reasons: have groups with spaces in them.
             provide ultimate safety/futureproof with -0

??
reasonable?